What an unusual question. What makes you want to drink the juice from a vine? If you are asking if liquid coming from a vine is a sign that your pumpkins are bad the answer is no. The liquid is just water and other nutrients for the plants growth, I wouldn't drink it but it isn't dangerous. Nothing you've described is a cause for concern. Did your plants get hit by frost? That can damage the pumpkins if it was cold enough, but that would be obvious because they will turn to mush.